Structure optimization of tailored ionic liquids and process simulation for shale gas separation

Shale gas, as a potential substitute for energy source, requires important processing steps before utilization. The most common separation technology applied is distillation, which is energy-intensive. With good stability, non-volatility, and tailored properties, ionic liquids (ILs) are regarded as novel potential solvents and alternative media for gas absorption. Therefore, a new strategy for hybrid shale gas separation processing, where IL-based absorption together with distillation is employed for energy-efficient and cost-economic gas processing, is developed. In this work, a three-stage methodology for shale gas separation process is proposed: IL screening, where a systematic screening method with two options (database screening and computer-aided design based on universal quasichemical functional-group activity coefficient model) is established; suitable ILs are selected as promising candidates; process design and simulation, where separation schemes and important design issues in the IL-based processes are determined; and, process evaluation, where the performance of the final separation process is evaluated and verified.